This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Polymavirus is latent in the kidney of up to 50% of healthy adults. In kidney transplant patients maintained on immunosuppressive drugs, reactivation of virus can result in polymovirus allograft nephropathy (PVAN). PVAN is an inadequately studied and distressing condidtion that frequently leads to graft loss. The study being proposed explores the notion that changes in viral genomic structure might play an important role in the initiation and subsequent progression of this disease